David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 1 | /* auditfilter.c -- filtering of audit events |
| 2 | * |
| 3 | * Copyright 2003-2004 Red Hat, Inc. |
| 4 | * Copyright 2005 Hewlett-Packard Development Company, L.P. |
| 5 | * Copyright 2005 IBM Corporation |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 20 | */ |
| 21 | |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/audit.h> |
| 24 | #include <linux/kthread.h> |
| 25 | #include <linux/netlink.h> |
| 26 | #include "audit.h" |
| 27 | |
| 28 | /* There are three lists of rules -- one to search at task creation |
| 29 | * time, one to search at syscall entry time, and another to search at |
| 30 | * syscall exit time. */ |
| 31 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
| 32 | LIST_HEAD_INIT(audit_filter_list[0]), |
| 33 | LIST_HEAD_INIT(audit_filter_list[1]), |
| 34 | LIST_HEAD_INIT(audit_filter_list[2]), |
| 35 | LIST_HEAD_INIT(audit_filter_list[3]), |
| 36 | LIST_HEAD_INIT(audit_filter_list[4]), |
| 37 | LIST_HEAD_INIT(audit_filter_list[5]), |
| 38 | #if AUDIT_NR_FILTERS != 6 |
| 39 | #error Fix audit_filter_list initialiser |
| 40 | #endif |
| 41 | }; |
| 42 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 43 | static inline void audit_free_rule(struct audit_entry *e) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 44 | { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 45 | kfree(e->rule.fields); |
| 46 | kfree(e); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 47 | } |
| 48 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 49 | static inline void audit_free_rule_rcu(struct rcu_head *head) |
| 50 | { |
| 51 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); |
| 52 | audit_free_rule(e); |
| 53 | } |
| 54 | |
| 55 | /* Unpack a filter field's string representation from user-space |
| 56 | * buffer. */ |
| 57 | static __attribute__((unused)) char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
| 58 | { |
| 59 | char *str; |
| 60 | |
| 61 | if (!*bufp || (len == 0) || (len > *remain)) |
| 62 | return ERR_PTR(-EINVAL); |
| 63 | |
| 64 | /* Of the currently implemented string fields, PATH_MAX |
| 65 | * defines the longest valid length. |
| 66 | */ |
| 67 | if (len > PATH_MAX) |
| 68 | return ERR_PTR(-ENAMETOOLONG); |
| 69 | |
| 70 | str = kmalloc(len + 1, GFP_KERNEL); |
| 71 | if (unlikely(!str)) |
| 72 | return ERR_PTR(-ENOMEM); |
| 73 | |
| 74 | memcpy(str, *bufp, len); |
| 75 | str[len] = 0; |
| 76 | *bufp += len; |
| 77 | *remain -= len; |
| 78 | |
| 79 | return str; |
| 80 | } |
| 81 | |
| 82 | /* Common user-space to kernel rule translation. */ |
| 83 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) |
| 84 | { |
| 85 | unsigned listnr; |
| 86 | struct audit_entry *entry; |
| 87 | struct audit_field *fields; |
| 88 | int i, err; |
| 89 | |
| 90 | err = -EINVAL; |
| 91 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; |
| 92 | switch(listnr) { |
| 93 | default: |
| 94 | goto exit_err; |
| 95 | case AUDIT_FILTER_USER: |
| 96 | case AUDIT_FILTER_TYPE: |
| 97 | #ifdef CONFIG_AUDITSYSCALL |
| 98 | case AUDIT_FILTER_ENTRY: |
| 99 | case AUDIT_FILTER_EXIT: |
| 100 | case AUDIT_FILTER_TASK: |
| 101 | #endif |
| 102 | ; |
| 103 | } |
| 104 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_POSSIBLE && |
| 105 | rule->action != AUDIT_ALWAYS) |
| 106 | goto exit_err; |
| 107 | if (rule->field_count > AUDIT_MAX_FIELDS) |
| 108 | goto exit_err; |
| 109 | |
| 110 | err = -ENOMEM; |
| 111 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); |
| 112 | if (unlikely(!entry)) |
| 113 | goto exit_err; |
| 114 | fields = kmalloc(sizeof(*fields) * rule->field_count, GFP_KERNEL); |
| 115 | if (unlikely(!fields)) { |
| 116 | kfree(entry); |
| 117 | goto exit_err; |
| 118 | } |
| 119 | |
| 120 | memset(&entry->rule, 0, sizeof(struct audit_krule)); |
| 121 | memset(fields, 0, sizeof(struct audit_field)); |
| 122 | |
| 123 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; |
| 124 | entry->rule.listnr = listnr; |
| 125 | entry->rule.action = rule->action; |
| 126 | entry->rule.field_count = rule->field_count; |
| 127 | entry->rule.fields = fields; |
| 128 | |
| 129 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
| 130 | entry->rule.mask[i] = rule->mask[i]; |
| 131 | |
| 132 | return entry; |
| 133 | |
| 134 | exit_err: |
| 135 | return ERR_PTR(err); |
| 136 | } |
| 137 | |
| 138 | /* Translate struct audit_rule to kernel's rule respresentation. |
| 139 | * Exists for backward compatibility with userspace. */ |
| 140 | static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) |
| 141 | { |
| 142 | struct audit_entry *entry; |
| 143 | int err = 0; |
| 144 | int i; |
| 145 | |
| 146 | entry = audit_to_entry_common(rule); |
| 147 | if (IS_ERR(entry)) |
| 148 | goto exit_nofree; |
| 149 | |
| 150 | for (i = 0; i < rule->field_count; i++) { |
| 151 | struct audit_field *f = &entry->rule.fields[i]; |
| 152 | |
| 153 | if (rule->fields[i] & AUDIT_UNUSED_BITS) { |
| 154 | err = -EINVAL; |
| 155 | goto exit_free; |
| 156 | } |
| 157 | |
| 158 | f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); |
| 159 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); |
| 160 | f->val = rule->values[i]; |
| 161 | |
| 162 | entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; |
| 163 | if (f->op & AUDIT_NEGATE) |
| 164 | f->op |= AUDIT_NOT_EQUAL; |
| 165 | else if (!(f->op & AUDIT_OPERATORS)) |
| 166 | f->op |= AUDIT_EQUAL; |
| 167 | f->op &= ~AUDIT_NEGATE; |
| 168 | } |
| 169 | |
| 170 | exit_nofree: |
| 171 | return entry; |
| 172 | |
| 173 | exit_free: |
| 174 | audit_free_rule(entry); |
| 175 | return ERR_PTR(err); |
| 176 | } |
| 177 | |
| 178 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
| 179 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, |
| 180 | size_t datasz) |
| 181 | { |
| 182 | int err = 0; |
| 183 | struct audit_entry *entry; |
| 184 | void *bufp; |
| 185 | /* size_t remain = datasz - sizeof(struct audit_rule_data); */ |
| 186 | int i; |
| 187 | |
| 188 | entry = audit_to_entry_common((struct audit_rule *)data); |
| 189 | if (IS_ERR(entry)) |
| 190 | goto exit_nofree; |
| 191 | |
| 192 | bufp = data->buf; |
| 193 | entry->rule.vers_ops = 2; |
| 194 | for (i = 0; i < data->field_count; i++) { |
| 195 | struct audit_field *f = &entry->rule.fields[i]; |
| 196 | |
| 197 | err = -EINVAL; |
| 198 | if (!(data->fieldflags[i] & AUDIT_OPERATORS) || |
| 199 | data->fieldflags[i] & ~AUDIT_OPERATORS) |
| 200 | goto exit_free; |
| 201 | |
| 202 | f->op = data->fieldflags[i] & AUDIT_OPERATORS; |
| 203 | f->type = data->fields[i]; |
| 204 | switch(f->type) { |
| 205 | /* call type-specific conversion routines here */ |
| 206 | default: |
| 207 | f->val = data->values[i]; |
| 208 | } |
| 209 | } |
| 210 | |
| 211 | exit_nofree: |
| 212 | return entry; |
| 213 | |
| 214 | exit_free: |
| 215 | audit_free_rule(entry); |
| 216 | return ERR_PTR(err); |
| 217 | } |
| 218 | |
| 219 | /* Pack a filter field's string representation into data block. */ |
| 220 | static inline size_t audit_pack_string(void **bufp, char *str) |
| 221 | { |
| 222 | size_t len = strlen(str); |
| 223 | |
| 224 | memcpy(*bufp, str, len); |
| 225 | *bufp += len; |
| 226 | |
| 227 | return len; |
| 228 | } |
| 229 | |
| 230 | /* Translate kernel rule respresentation to struct audit_rule. |
| 231 | * Exists for backward compatibility with userspace. */ |
| 232 | static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) |
| 233 | { |
| 234 | struct audit_rule *rule; |
| 235 | int i; |
| 236 | |
| 237 | rule = kmalloc(sizeof(*rule), GFP_KERNEL); |
| 238 | if (unlikely(!rule)) |
| 239 | return ERR_PTR(-ENOMEM); |
| 240 | memset(rule, 0, sizeof(*rule)); |
| 241 | |
| 242 | rule->flags = krule->flags | krule->listnr; |
| 243 | rule->action = krule->action; |
| 244 | rule->field_count = krule->field_count; |
| 245 | for (i = 0; i < rule->field_count; i++) { |
| 246 | rule->values[i] = krule->fields[i].val; |
| 247 | rule->fields[i] = krule->fields[i].type; |
| 248 | |
| 249 | if (krule->vers_ops == 1) { |
| 250 | if (krule->fields[i].op & AUDIT_NOT_EQUAL) |
| 251 | rule->fields[i] |= AUDIT_NEGATE; |
| 252 | } else { |
| 253 | rule->fields[i] |= krule->fields[i].op; |
| 254 | } |
| 255 | } |
| 256 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; |
| 257 | |
| 258 | return rule; |
| 259 | } |
| 260 | |
| 261 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
| 262 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) |
| 263 | { |
| 264 | struct audit_rule_data *data; |
| 265 | void *bufp; |
| 266 | int i; |
| 267 | |
| 268 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); |
| 269 | if (unlikely(!data)) |
| 270 | return ERR_PTR(-ENOMEM); |
| 271 | memset(data, 0, sizeof(*data)); |
| 272 | |
| 273 | data->flags = krule->flags | krule->listnr; |
| 274 | data->action = krule->action; |
| 275 | data->field_count = krule->field_count; |
| 276 | bufp = data->buf; |
| 277 | for (i = 0; i < data->field_count; i++) { |
| 278 | struct audit_field *f = &krule->fields[i]; |
| 279 | |
| 280 | data->fields[i] = f->type; |
| 281 | data->fieldflags[i] = f->op; |
| 282 | switch(f->type) { |
| 283 | /* call type-specific conversion routines here */ |
| 284 | default: |
| 285 | data->values[i] = f->val; |
| 286 | } |
| 287 | } |
| 288 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; |
| 289 | |
| 290 | return data; |
| 291 | } |
| 292 | |
| 293 | /* Compare two rules in kernel format. Considered success if rules |
| 294 | * don't match. */ |
| 295 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 296 | { |
| 297 | int i; |
| 298 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 299 | if (a->flags != b->flags || |
| 300 | a->listnr != b->listnr || |
| 301 | a->action != b->action || |
| 302 | a->field_count != b->field_count) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 303 | return 1; |
| 304 | |
| 305 | for (i = 0; i < a->field_count; i++) { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 306 | if (a->fields[i].type != b->fields[i].type || |
| 307 | a->fields[i].op != b->fields[i].op) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 308 | return 1; |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 309 | |
| 310 | switch(a->fields[i].type) { |
| 311 | /* call type-specific comparison routines here */ |
| 312 | default: |
| 313 | if (a->fields[i].val != b->fields[i].val) |
| 314 | return 1; |
| 315 | } |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 316 | } |
| 317 | |
| 318 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
| 319 | if (a->mask[i] != b->mask[i]) |
| 320 | return 1; |
| 321 | |
| 322 | return 0; |
| 323 | } |
| 324 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 325 | /* Add rule to given filterlist if not a duplicate. Protected by |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 326 | * audit_netlink_sem. */ |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 327 | static inline int audit_add_rule(struct audit_entry *entry, |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 328 | struct list_head *list) |
| 329 | { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 330 | struct audit_entry *e; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 331 | |
| 332 | /* Do not use the _rcu iterator here, since this is the only |
| 333 | * addition routine. */ |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 334 | list_for_each_entry(e, list, list) { |
| 335 | if (!audit_compare_rule(&entry->rule, &e->rule)) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 336 | return -EEXIST; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 337 | } |
| 338 | |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 339 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 340 | list_add_rcu(&entry->list, list); |
| 341 | } else { |
| 342 | list_add_tail_rcu(&entry->list, list); |
| 343 | } |
| 344 | |
| 345 | return 0; |
| 346 | } |
| 347 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 348 | /* Remove an existing rule from filterlist. Protected by |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 349 | * audit_netlink_sem. */ |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 350 | static inline int audit_del_rule(struct audit_entry *entry, |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 351 | struct list_head *list) |
| 352 | { |
| 353 | struct audit_entry *e; |
| 354 | |
| 355 | /* Do not use the _rcu iterator here, since this is the only |
| 356 | * deletion routine. */ |
| 357 | list_for_each_entry(e, list, list) { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 358 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 359 | list_del_rcu(&e->list); |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 360 | call_rcu(&e->rcu, audit_free_rule_rcu); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 361 | return 0; |
| 362 | } |
| 363 | } |
| 364 | return -ENOENT; /* No matching rule */ |
| 365 | } |
| 366 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 367 | /* List rules using struct audit_rule. Exists for backward |
| 368 | * compatibility with userspace. */ |
| 369 | static int audit_list(void *_dest) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 370 | { |
| 371 | int pid, seq; |
| 372 | int *dest = _dest; |
| 373 | struct audit_entry *entry; |
| 374 | int i; |
| 375 | |
| 376 | pid = dest[0]; |
| 377 | seq = dest[1]; |
| 378 | kfree(dest); |
| 379 | |
| 380 | down(&audit_netlink_sem); |
| 381 | |
| 382 | /* The *_rcu iterators not needed here because we are |
| 383 | always called with audit_netlink_sem held. */ |
| 384 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 385 | list_for_each_entry(entry, &audit_filter_list[i], list) { |
| 386 | struct audit_rule *rule; |
| 387 | |
| 388 | rule = audit_krule_to_rule(&entry->rule); |
| 389 | if (unlikely(!rule)) |
| 390 | break; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 391 | audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 392 | rule, sizeof(*rule)); |
| 393 | kfree(rule); |
| 394 | } |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 395 | } |
| 396 | audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
| 397 | |
| 398 | up(&audit_netlink_sem); |
| 399 | return 0; |
| 400 | } |
| 401 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 402 | /* List rules using struct audit_rule_data. */ |
| 403 | static int audit_list_rules(void *_dest) |
| 404 | { |
| 405 | int pid, seq; |
| 406 | int *dest = _dest; |
| 407 | struct audit_entry *e; |
| 408 | int i; |
| 409 | |
| 410 | pid = dest[0]; |
| 411 | seq = dest[1]; |
| 412 | kfree(dest); |
| 413 | |
| 414 | down(&audit_netlink_sem); |
| 415 | |
| 416 | /* The *_rcu iterators not needed here because we are |
| 417 | always called with audit_netlink_sem held. */ |
| 418 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
| 419 | list_for_each_entry(e, &audit_filter_list[i], list) { |
| 420 | struct audit_rule_data *data; |
| 421 | |
| 422 | data = audit_krule_to_data(&e->rule); |
| 423 | if (unlikely(!data)) |
| 424 | break; |
| 425 | audit_send_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
| 426 | data, sizeof(*data)); |
| 427 | kfree(data); |
| 428 | } |
| 429 | } |
| 430 | audit_send_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
| 431 | |
| 432 | up(&audit_netlink_sem); |
| 433 | return 0; |
| 434 | } |
| 435 | |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 436 | /** |
| 437 | * audit_receive_filter - apply all rules to the specified message type |
| 438 | * @type: audit message type |
| 439 | * @pid: target pid for netlink audit messages |
| 440 | * @uid: target uid for netlink audit messages |
| 441 | * @seq: netlink audit message sequence (serial) number |
| 442 | * @data: payload data |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 443 | * @datasz: size of payload data |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 444 | * @loginuid: loginuid of sender |
| 445 | */ |
| 446 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 447 | size_t datasz, uid_t loginuid) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 448 | { |
| 449 | struct task_struct *tsk; |
| 450 | int *dest; |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 451 | int err = 0; |
| 452 | struct audit_entry *entry; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 453 | |
| 454 | switch (type) { |
| 455 | case AUDIT_LIST: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 456 | case AUDIT_LIST_RULES: |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 457 | /* We can't just spew out the rules here because we might fill |
| 458 | * the available socket buffer space and deadlock waiting for |
| 459 | * auditctl to read from it... which isn't ever going to |
| 460 | * happen if we're actually running in the context of auditctl |
| 461 | * trying to _send_ the stuff */ |
| 462 | |
| 463 | dest = kmalloc(2 * sizeof(int), GFP_KERNEL); |
| 464 | if (!dest) |
| 465 | return -ENOMEM; |
| 466 | dest[0] = pid; |
| 467 | dest[1] = seq; |
| 468 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 469 | if (type == AUDIT_LIST) |
| 470 | tsk = kthread_run(audit_list, dest, "audit_list"); |
| 471 | else |
| 472 | tsk = kthread_run(audit_list_rules, dest, |
| 473 | "audit_list_rules"); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 474 | if (IS_ERR(tsk)) { |
| 475 | kfree(dest); |
| 476 | err = PTR_ERR(tsk); |
| 477 | } |
| 478 | break; |
| 479 | case AUDIT_ADD: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 480 | case AUDIT_ADD_RULE: |
| 481 | if (type == AUDIT_ADD) |
| 482 | entry = audit_rule_to_entry(data); |
| 483 | else |
| 484 | entry = audit_data_to_entry(data, datasz); |
| 485 | if (IS_ERR(entry)) |
| 486 | return PTR_ERR(entry); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 487 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 488 | err = audit_add_rule(entry, |
| 489 | &audit_filter_list[entry->rule.listnr]); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 490 | if (!err) |
| 491 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, |
| 492 | "auid=%u added an audit rule\n", loginuid); |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 493 | else |
| 494 | audit_free_rule(entry); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 495 | break; |
| 496 | case AUDIT_DEL: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 497 | case AUDIT_DEL_RULE: |
| 498 | if (type == AUDIT_DEL) |
| 499 | entry = audit_rule_to_entry(data); |
| 500 | else |
| 501 | entry = audit_data_to_entry(data, datasz); |
| 502 | if (IS_ERR(entry)) |
| 503 | return PTR_ERR(entry); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 504 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 505 | err = audit_del_rule(entry, |
| 506 | &audit_filter_list[entry->rule.listnr]); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 507 | if (!err) |
| 508 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, |
| 509 | "auid=%u removed an audit rule\n", loginuid); |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 510 | audit_free_rule(entry); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 511 | break; |
| 512 | default: |
| 513 | return -EINVAL; |
| 514 | } |
| 515 | |
| 516 | return err; |
| 517 | } |
| 518 | |
| 519 | int audit_comparator(const u32 left, const u32 op, const u32 right) |
| 520 | { |
| 521 | switch (op) { |
| 522 | case AUDIT_EQUAL: |
| 523 | return (left == right); |
| 524 | case AUDIT_NOT_EQUAL: |
| 525 | return (left != right); |
| 526 | case AUDIT_LESS_THAN: |
| 527 | return (left < right); |
| 528 | case AUDIT_LESS_THAN_OR_EQUAL: |
| 529 | return (left <= right); |
| 530 | case AUDIT_GREATER_THAN: |
| 531 | return (left > right); |
| 532 | case AUDIT_GREATER_THAN_OR_EQUAL: |
| 533 | return (left >= right); |
| 534 | default: |
| 535 | return -EINVAL; |
| 536 | } |
| 537 | } |
| 538 | |
| 539 | |
| 540 | |
| 541 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 542 | struct audit_krule *rule, |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 543 | enum audit_state *state) |
| 544 | { |
| 545 | int i; |
| 546 | |
| 547 | for (i = 0; i < rule->field_count; i++) { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 548 | struct audit_field *f = &rule->fields[i]; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 549 | int result = 0; |
| 550 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 551 | switch (f->type) { |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 552 | case AUDIT_PID: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 553 | result = audit_comparator(cb->creds.pid, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 554 | break; |
| 555 | case AUDIT_UID: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 556 | result = audit_comparator(cb->creds.uid, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 557 | break; |
| 558 | case AUDIT_GID: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 559 | result = audit_comparator(cb->creds.gid, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 560 | break; |
| 561 | case AUDIT_LOGINUID: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 562 | result = audit_comparator(cb->loginuid, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 563 | break; |
| 564 | } |
| 565 | |
| 566 | if (!result) |
| 567 | return 0; |
| 568 | } |
| 569 | switch (rule->action) { |
| 570 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; |
| 571 | case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break; |
| 572 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
| 573 | } |
| 574 | return 1; |
| 575 | } |
| 576 | |
| 577 | int audit_filter_user(struct netlink_skb_parms *cb, int type) |
| 578 | { |
| 579 | struct audit_entry *e; |
| 580 | enum audit_state state; |
| 581 | int ret = 1; |
| 582 | |
| 583 | rcu_read_lock(); |
| 584 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { |
| 585 | if (audit_filter_user_rules(cb, &e->rule, &state)) { |
| 586 | if (state == AUDIT_DISABLED) |
| 587 | ret = 0; |
| 588 | break; |
| 589 | } |
| 590 | } |
| 591 | rcu_read_unlock(); |
| 592 | |
| 593 | return ret; /* Audit by default */ |
| 594 | } |
| 595 | |
| 596 | int audit_filter_type(int type) |
| 597 | { |
| 598 | struct audit_entry *e; |
| 599 | int result = 0; |
| 600 | |
| 601 | rcu_read_lock(); |
| 602 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) |
| 603 | goto unlock_and_return; |
| 604 | |
| 605 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], |
| 606 | list) { |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 607 | int i; |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame^] | 608 | for (i = 0; i < e->rule.field_count; i++) { |
| 609 | struct audit_field *f = &e->rule.fields[i]; |
| 610 | if (f->type == AUDIT_MSGTYPE) { |
| 611 | result = audit_comparator(type, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 612 | if (!result) |
| 613 | break; |
| 614 | } |
| 615 | } |
| 616 | if (result) |
| 617 | goto unlock_and_return; |
| 618 | } |
| 619 | unlock_and_return: |
| 620 | rcu_read_unlock(); |
| 621 | return result; |
| 622 | } |